German news site Heise has an article about a Swiss-designed airship that can function as a mobile phone mast. For those who don't read German, here's a translation (from my third into my second language, but I'm confident it's accurate).

Swiss develop flying mobile broadcast antenna

A team of Swiss scientists and entrepreneurs have developed a flying base station for mobile communications, designed to replace antenna masts on the ground. The "X-Station" consists of a Helium-filled 60 meter long zeppelin, and a platform, which will ascend to 21 km and remain in place. Connected to the zeppelin is a small unmanned airplane, Swiss television reports. Mobile phone radiation is reduced a thousandfold according to the designers.

Swiss inventor Kamal Allawi came up with the idea for the project. More than 50 scientists of the federal polytechnical universities of ZÃ¼rich and Lausanne, of the University of Neuenburg as well as the federal material sciences institute worked on the realisation at one point or another. Technology company RUAG Aerospace was also involved. To keep the X-Station in position, an auto pilot with GPS was developed. The small plane will be equipped with giant propellors to counteract the strong winds at this altitude. A prototype of the craft, the full version of which is estimated to cost 30 to 40 million Francs (19 to 25.5 million euro), is planned to take off next year.

A single X-Station will be able to cover an area the size of Switzerland; covering all of Europe will take about 20 stations. As well as providing telephone, internet, digital radio and television coverage the craft could be equipped with a camera for surveillance purposes, for example for monitoring forest fires. (anw/c't)